The command takes two arguments. The file to unpack and the directory to unpack it into. You seem to be giving it more than two arguments, but you haven't given the command you issued, so exactly what's wrong is a mystery.

The command takes two arguments. The file to unpack and the directory to unpack it into. You seem to be giving it more than two arguments, but you haven't given the command you issued, so exactly what's wrong is a mystery.

There is some new header field (or other black magic) that decide if book with field 501 = EBOK should be put in Comics not Books category.

My best guess is that the "comic" category is not determined by the book contents, but comes from Amazon's servers.

As a test I put my Oasis in airplane mode, bought a (free) comic, downloaded it and copied it to the Oasis via USB. It did not show as a comic. I then turned off airplane mode and synced the kindle. After that the sideloaded book showed as a comic.

As another test I took a book that showed as a comic and made a copy of it with a different (unused) ASIN. The copy did not show as a comic even though the book contents were identical to the original book, other than the ASIN.

My best guess is that the "comic" category is not determined by the book contents, but comes from Amazon's servers.

As a test I put my Oasis in airplane mode, bought a (free) comic, downloaded it and copied it to the Oasis via USB. It did not show as a comic. I then turned off airplane mode and synced the kindle. After that the sideloaded book showed as a comic.

As another test I took a book that showed as a comic and made a copy of it with a different (unused) ASIN. The copy did not show as a comic even though the book contents were identical to the original book, other than the ASIN.

Well played Amazon. Forcing remote query to check information that is available in file header.

Amazon has been doing that for years. The earliest example, I can remember is when they refused to display thumbnails for books unless the thumbnails are downloaded from Amazon even though the files have perfectly good thumbnails in their metadata, this was back in 2010-2011 IIRC

Amazon has been gradually trying to make side-loading less and less pleasant on their platforms for a very long time.